Method for forming Ti-containing film by PEALD using TDMAT or TDEAT

Abstract

A method for forming a Ti-containing film on a substrate by plasma-enhanced atomic layer deposition (PEALD) using tetrakis(dimethylamino)titanium (TDMAT) or tetrakis(diethylamino)titanium (TDEAT), includes: introducing TDMAT and/or TDEAT in a pulse to a reaction space where a substrate is placed; continuously introducing a NH 3 -free reactant gas to the reaction space; applying RF power in a pulse to the reaction space wherein the pulse of TDMAT and/or TDEAT and the pulse of RF power do not overlap; and repeating the above steps to deposit a Ti-containing film on the substrate.

The invention claimed is: 
     
       1. A method for forming a TiN film on a substrate by plasma-enhanced atomic layer deposition (PEALD) using tetrakis(dimethylamino)titanium (TDMAT) or tetrakis(diethylamino)titanium (TDEAT), said PEALD comprising multiple deposition cycles, each deposition cycle comprising:
 (i) introducing TDMAT and/or TDEAT in a pulse to a reaction space where a substrate is placed; 
 (ii) continuously introducing a NH 3 -free reactant gas to the reaction space, wherein the NH 3 -free reactant gas contains neither nitrogen nor oxygen atoms and wherein the NH 3 -free reactant gas is H 2 ; and 
 (iii) applying RF power in a pulse to the reaction space wherein the pulse of TDMAT and/or TDEAT and the pulse of RF power do not overlap; and 
 wherein (iv) steps (i) to (iii) are repeated to deposit a TiN film on the substrate, and 
 said method further comprising: 
 setting a target film stress for the TiN film, which is greater than a film stress of a reference TiN crystalline film being deposited by steps (i) to (iv) under deposition conditions including a reference flow rate of H 2  used as the reactant gas in step (ii), and reference RF power used in step (iii); and 
 setting a flow rate of H 2  used as the reactant gas in step (ii), and RF power used in step (iii), wherein only one or more of the flow rate of H 2 , and the RF power are used as control parameters for changing the film stress, and are different from the reference flow rate of H 2  and the reference RF power, followed by conducting steps (i) to (iv) for depositing the TiN film. 
 
     
     
       2. The method according to  claim 1 , wherein the NH 3 -free reactant gas consists of H 2  and a rare gas, thereby depositing a TiN crystalline film. 
     
     
       3. The method according to  claim 1 , wherein the TiN film has a film stress of −2,500 MPa to 800 MPa. 
     
     
       4. The method according to  claim 1 , wherein the TiN film has tensile film stress. 
     
     
       5. The method according to  claim 4 , wherein the set flow rate of H 2  is lower than the reference flow rate of H 2  used for the reference TiN crystalline film. 
     
     
       6. The method according to  claim 4 , wherein the set RF power is lower than the reference RF power used for the reference TiN crystalline film. 
     
     
       7. The method according to  claim 4 , wherein the Ti-containing film contains about 4% to about 9% carbon. 
     
     
       8. The method according to  claim 4 , wherein the Ti-containing film shows a peak at 2,000 cm −1  and substantially no peak at 1,400 cm −1  in a Fourier Transform Infrared Spectroscopy (FT-IR) graph.